Re: FWD: FLOATING-POINT CONSISTENCY, -FFLOAT-STORE, AND X86

[Craig Burley <burley at gnu dot org>]

>It is safe in the sence that the language may not require evaluating
>(a*b*c*d) in a specific order (ANSI C doesn't afaik).  However for FP,
>it can give different results.  Think overflow for example, or when
>rounding is set to infinity, you have: 0.1 * (0.1 * -1) != (0.1 * 0.1) * -1

Correct.  Nor does *any* version of Fortran -- *the* language
for high-speed scientific/numeric programming -- mandate evaluation
of expressions like a*b*c*d in any particular order.

I don't think I want to spend my valuable time correcting people on
language issues, when they can read the standards, and the discussions
already taking place among experts on the Internet, for themselves.

So, Sylvain, Joe Buck, and others, thanks for helping correct people
who seem to have appeared out of the woodwork to argue against a
very reasonable proposal using non-existant requirements regarding
numerics among the Fortran, C, and IEEE standards!

        tq vm, (burley)